Bus: SQUAKE
Calculate bus travel emissions with the SQUAKE methodology, which can use operator-specific data and fuel type for a more accurate result.
About the methodology
SQUAKE's approach to bus carbon calculation stands out for integrating operator-specific data. Buses can vary widely in environmental impact depending on many variables: bus age, fuel type, maintenance schedules, route frequencies and driver habits can all play a role in the carbon footprint of a single journey.
SQUAKE aggregates broad industry metrics and also narrows down to individual bus operators. This lets transportation authorities and companies gain precise insights and target their carbon reduction strategies.
Sample requests
Send a quote before booking, then repeat the call with audit set to true once the booking is final. The body is otherwise identical.
{
"expand": ["items"],
"items": [{
"audit": false,
"type": "bus",
"external_reference": "test_1",
"origin": "Berlin",
"destination": "Frankfurt am Main",
"number_of_travelers": 1,
"methodology": "SQUAKE",
"fuel_type": "diesel",
"operator_name": "flixbus"
}]
}audit_for is optional
Pass the ID of an auditable entity when you calculate on behalf of that entity. Otherwise, leave it out.
Defaults
| Field | Default | Applies when |
|---|---|---|
fuel_type | average | No fuel_type is sent |
number_of_travelers | 1 | No number_of_travelers is sent |
Request fields
typestringrequiredbus
methodologystringrequiredSQUAKE
external_referencestringYour identifier for the item, up to 128 characters, so you can link the resulting emissions to the requested item. Especially useful when you request multiple items, because SQUAKE doesn't guarantee to keep the same order.
number_of_travelersintegerMinimum 1. Defaults to 1.
originstringSQUAKE tries to resolve it whatever its format. See Origin and destination formats.
destinationstringSame formats as origin.
distance_in_kmnumberTakes priority over origin and destination. Without it, SQUAKE resolves the distance from origin and destination. If you send both, SQUAKE uses distance_in_km.
fuel_typeenumlng, diesel, lpg, phev, hydrogen, electricity. Defaults to average.
operator_namestringPass the operator's name to get a more accurate result. See the list of supported operators.
auditbooleanSet to true to create immutable audit records for finalised calculations. Must be enabled for your account.
POST /v2/calculations in the API referenceOrigin and destination formats
SQUAKE tries to resolve origin and destination whatever their format. Ideally, use:
- Addresses: the Post standard.
- Airports: an IATA/ICAO code (regex
^[A-Z]{3,4}$, for example"MUC"). - Ports and trade locations: a UN/LOCODE (regex
^[A-Z]{2}\W?[A-Z2-9]{3}$, for example"DEHAM"). - Coordinates: latitude and longitude (regex
^[-+]?\d{1,3}\.\d{1,10}\s?,\s?[-+]?\d{1,3}\.\d{1,10}$, for example"+40.712,-74.006").
Provider and stop codes for buses
You can also reference bus stops or stations with provider-prefixed stop IDs, in the format <provider>:<stop_id> (for example flixbus:2006). Common provider prefixes: flixbus, distribusion, busbud.
Fallback
If a value can't be resolved, SQUAKE falls back to generic (non-journey-specific) bus factors under the SQUAKE methodology.
{
"type": "bus",
"methodology": "SQUAKE",
"origin": "flixbus:berlin_zob",
"destination": "flixbus:frankfurt_sued",
"operator_name": "flixbus",
"number_of_travelers": 1
}Sample response
{
"carbon_quantity": 12374,
"carbon_unit": "gram",
"items": [{
"carbon_quantity": 12374,
"carbon_unit": "gram",
"external_reference": "test_1",
"type": "bus",
"methodology": "SQUAKE",
"distance": 538.0,
"distance_unit": "kilometer"
}]
}Bibliography
- Chang, Ching-Chih, et al. "Life Cycle Assessment of Carbon Footprint in Public Transportation - a Case Study of Bus Route NO. 2 in Tainan City, Taiwan." Procedia Manufacturing, vol. 30, Elsevier BV, 2019, pp. 388–95. doi:10.1016/j.promfg.2019.02.054.
- Logan, Kathryn G., et al. "Electric and Hydrogen Buses: Shifting From Conventionally Fuelled Cars in the UK." Transportation Research Part D: Transport and Environment, vol. 85, Elsevier BV, Aug. 2020, p. 102350. doi:10.1016/j.trd.2020.102350.
- "Which form of transport has the smallest carbon footprint?" Our World in Data, ourworldindata.org/travel-carbon-footprint.